Stipa comata - Carex filifolia Plant Association 



STICOM - CARFIL; needle-and-thread (-) threadleaf sedge 



MTNHP rank: G5/S4 



Environment: This is the predominant grassland type in Carter County on uplands with soils 

 derived from sandstone parent materials; it occurs on planar surfaces, gently rollmg plateaus, tops of 

 buttes, and gentle slopes of all aspects, though it is more prevalent on warmer exposures. It is most 

 consistently found in shallow to gravel range sites, but is in a variety of others. STIC0N4/CARFIL is 

 also consistently found in well-developed sandplains representing sands or sandy range sites, though 

 such settings are nearly absent from BLM land in Carter County. 



Vegetation: In the five plots of STICOM/CARFIL sampled, 62 species were tallied (Appendix A). 

 Although Stipa comata is the more conspicuous of the codominant graminoids (both with an average 

 cover of 36%) Carex filifolia had greater cover in three of the plots. Cover by Stipa comata ranged 

 from 20 to 70% and cover by Carex filifolia ranged from 10 to 60 %. These canopy cover values are 

 decidedly less (by an average of 40 and 18 %) than reported by Hansen and Hoffman (1988) for the 

 same association, in the same vicinity. This discrepancy in productivity could be explained by year 

 of sampling, past grazing history and the higher elevations (inferred greater precipitation) of the 

 Hansen & Hoffman plots. 



No other grasses were 100 % constant but, a rhizomatous wheatgrass, either Pascopyrum smithii or 

 Elymus lanceolatus, and Bouteloua gracilis were sometimes well represented (up to 10% cover) and 

 occurred in 80 % of the plots. The subshrub Artemisia frigida was the only woody species with over 

 50% constancy. The diversity of forbs varied greatly between plots and is believed to be a reflection 

 of grazing regime. One plot, apparently ungrazed in recent years, had 18 forb species, while a plot 

 with evidence of heavy use by sheep in recent years had only 8 species. Forbs with high constancy (> 

 60%) included Cirsium undulatum, Lygodesmiajuncea, Opuntia polyacantha, Phlox hoodii, 

 Plantago patagonica, Psoralea argophylla, Sphaeralcea coccinea, and Tragopogon dubius. The 

 fact that all the previously mentioned species are "increased' or weedy may infer a generally poor 

 condition of the sampled stands of this association or alternatively they may simply constitute the 

 native composition of this type. Judging by the data of Hansen and Hoffman, who patiently sought 

 out relict or relatively undisturbed stands, this composition does not reflect a degraded condition; 

 one can speculate that if these plots represent degraded examples then the canopy cover of annual 

 brome grasses would be greater. The clubmoss, Selaginella densa is 80 % constant and well 

 represented in two plots currently grazed by sheep. 



Adjacent communities commonly include Pinus ponderosa communities on slopes and ridges, and 

 Artemisia cana communities (ARTCAN/PASSMI) on downslope alluvial terraces and in swales of 

 upland slopes. However, most frequently STICOM - CARFIL grades to Pascopyrum smithii-, or 

 Artemisia tridentata ssp. wyomingensis-domimXedi matrix type plant communities, such as 

 ARTTSW / ELYLAN or ELYLAN -BOUGRA- CARFIL. Patches of Calamovilfa longifolia/ 

 Carex inops are often included within the larger matrices of STICOM/CARFIL, usually in water 

 collecting positions. Along sandstone/shale contact zones there is often an abrupt transition from 

 STICOM/CARFIL on sandy soils (often the higher positions in the landscape) to grasslands or 



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